why IE7 javascript array.indexOf is not working? [duplicate]

Question

why in IE7 javascript array.indexOf is not working? Here is one sample

function loaderFn()
{
    var arr=["0","1","2"];
    var b = arr.indexOf("1")
    alert("Index of 1 is "+b);
}

In IE7 in line 4 (arr.indexOf("1"))

Object doesn't support property or method 'indexOf' error throws

Why this hapening only in IE7? What is the way to find index no of a value in array using javascript for IE7?

Answer 1

Add this in your document.ready method:

if(!Array.prototype.indexOf) {
    Array.prototype.indexOf = function(obj, start) {
         for (var i = (start || 0), j = this.length; i < j; i++) {
             if (this[i] === obj) { return i; }
         }
         return -1;
    }
}

This is needed because IE does not include this method up to IE8. The above function checks if it exists, if not it extends the Array prototype with it.